Toothbrush



Patented Dec. 21, 1926.

UNITED STATES PATENT Fries.

TOOTI-IBRUSH.

'Application med August 1, 1924, serial No.

lVIy invention relates to improvements in tooth brushes, the object of the same being to provide a hygienic tooth brush which is constructed in such a manner that the brush 5 portion can be thoroughly cleansed and will prevent the accumulation of foreign matter which at present takes place at the base of the tufts of bristles in tooth brushes of ordinary construction.

Hitherto it has been customary to make the tooth brush from one continuous piece of bone, ivory, Celluloid, or similar material, holes being bored at one end thereof into which tufts of bristles are introduced and f are held therein by cement, fine wire or other structural material.

The bristles of such brushes are arranged closely together and usually are assembled in three or more rows. Examination of such brushes aftertliey have been in use for some time shows that foreign matter, principally of food stuff accumulates at the base of the bristles and not only forms a harbour for bacteria but also sets up a deterioration or I rotting of the bristles which is intensified by the use of certain classes of dentifrice, parti cles of which also accumulate at the base of the bristles.

In order to overcome the disabilities above 3f referred to instead of malring the brush end in the manner previously described I form the base of the brush in separable parts or prongs, there being preferably thrlee such parts in parallel arrangement, the base itii' self being detachable from the handle.

But in order that my invention may be more clearly understood I will now describe the same by aid of the accompanying illustrative drawings wherein Fig. 1 is a side elevation of the tooth brush.

Fig. 2 is a plan of same with prongs fastened together with the clip.

Fig. 3 is a plan of tooth brush with prongs spread out to facilitate cleaning.

Fig. 4 is a modification of design of tooth brush.

Fig. 5 is an end view of brush.

Fig. 6 is a transverse sectional view through the prongs.

In each of the illustrations similar letters of reference are used todenote similar or corresponding parts wherever they occur.

In the drawings a is the butt end of the handle upon which one of the prongs, but preferably the middle prong b is permanently fastened or is made as an integral portion 729,478, ami iu Australia August as, 192s.

shown in Fig. 3, and the prongs are of a.

somewhat semi-circular or triangular formation in cross section and are otherwise so constructed as to leave small spaces g and t between the fixed prong and the pivoted prongs.

Upon the fixed prong I attach a fastening clip y' of any suitable design but in its preferred form it consists of a metal plate which is countersunk into the middle prong and securely fixedcthereto by a brad or rivet c, the ends of the clip being adapted to fit neatly into countersunlr recesses Z. and m formed in the pivoted arms andto slightly lapover the outer edges of said arms but without forming any appreciable projection.

The handle extension a may be either con- Y structed as a continuous portion of the butt or may have a screw threaded hole bored therein for the accommodation of a dowel or of the screw threaded extension o 'of the butt so that interchangeable handles or butts may be used.

In arranging the bristles I place at the outer end of the brush a row of long bristles p which may be four in number, two of which are fitted to the broadened portion of the end Iof the fixed arm, and rearward of these bristles I insert a series of short bristles g, the bristles being fitted according to usual custom, that it to say, if the handle is of bone or metal grooves are formed in the back of the brush and holes are drilled through the brush so that bristles can bev space for the fastening clip butv advantageously enables the long end bristles to be applied to the backs of the teeth With great freedom and Wi* hout causing damage to the adjacent bristles.

ln Fig. l l have shown a slight mod-Mication of the device but the basic principles of construction are sin ilar to those alreadj,7 V,de--

scribed, that is to say, there is a lined prong Z) forming a portion of the butt of the handle and provided 'with a fastenine' clip or cat-ch j and there is a hinged prong d adapted to lold in parallel arrangement with the lined prong` and when so l'olded a space is4 lett be tween the adjacent members.

Wlhen applied to practical usethe prongs are placed in the posit-ion indicated in Fig'. 2 and the brush may then be applied for the purposes ot' cleaning` the teeth. The slots primarily prevent an accumulation ol'- 'toregn matter at the base of' the bristles and after the cleaning` operation has been coinpleted the hinged prongs swing away from the lined portion and the cleaning of the roots of the bristles is easily ellected. The brushes may be constructed in Various sizes according to requirements and the handles may be standardized so that-the .saine handle may be used Ylor a number of brushes.

One o1 the parts may be an integral portion of the handle or of the butt oit the handle and can with advantage be from one eighth oi" an inch to a quarter of an inch in w'dth and is preferably bevelled along the sides so that it is somewhat semi-circular or triangular in formation in cross section.

This formation is not essential but lf prefer that the outer edges or prongs which are hinged to the butt end ol' the handle should be slightlyY rounded to facilita-te the arrange ment o' a fastening clip7 the prongs being suitably hinged to allenv them to be spread open, and the butt ot the handle maj,v be 'tur-- n'ishcd with a screw threaded portion to enable interchangcable ends or bam used.

l claim ln a tooth brush ol the character described the con'ibination of a plurality ot separable units haii' lo* ro'n's ot' tul'ts or bristle."7 exch row thereor lnlring a space adjacent the outer cnd and disposed between 'the outermost tuit oit bristles and the next adjacent tutt ol bristles, the length of the outer tutt ot bristles boing longer than the next adjacent tutt, and means carried by one ol said units in the said space and adapted to en gage over the other units in the correspond ing spaces.

ln testimony whereof I have alllxcd mj.' sigiiature.

FREDERICK RONALD WTOGDROW.

iles to lu 

